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March 3, 1964 P. 5. SAUNDERS LINES 0N PRINTI NG DIES METHOD AND DEVICE FOR P Sept. 29, 1961 3 Sheets-Sheet 1 ZNVENTOR. PHILIP G. SAUNDERS BY 2 2 ATTORNEYS March 1964 P. G. SAUNDERS METHOD AND DEVICE FOR PRODUCING REFERENCE LINES ON PRINTING DIES 3 Sheets-Sheet 2 Filed Sept. 29, 1961 INVENTQR. PHILIP G. SAUNDERS Y ATTORNEYS March 3, 1964 P. e. SAUNDERS 3,123,000

METHOD AND DEVICE FOR PRODUCING REFERENCE LINES ON PRINTING DIES 3 Sheets-Sheet 5 Filed Sept. 29. 1961 INVENTOR.

PHILIP G. SAUNDERS ATTORNEYS United States Patent ()fi ice 3,123,fi Patented Mar. 3, 1984 3,123,6(20 METHGD AND DEVICE F012 PRGDUCING REFERENCE LINES 9N PRINTHIG DIES Philip G. Saunders, 5315 Norton Place, Toledo 14, Ohio Filed Sept. 29, 1%1, Ser. No. 141,865 9 Claims. (Ql. 101-4911) This invention relates to an improved method and device for producing reference lines on printing dies.

In the art of printing, it is often desirable to provide reference lines and specifically centering lines on the printing dies to facilitate the proper location of the print. By way of example, accurate centering lines on printing dies are particularly important for printing containers of various types where the centering of the print on the sides or faces of the container must be closely held to establish a symmetrical and neat appearance. Accurately located reference lines are also important in multi-color printing processes where the proper placement of reference lines on each printing die enables the printing to be in proper register.

A printing die of the general type with which the present invention is concerned is made by first setting up a composite form using printing type, spacing blocks, and a frame in the usual manner known in the printing trade. The form may also include hand-cut hard rubber blocks for particular designs for part or all of the form, as is well known. From the form, a hard plastic mold is made and from the resulting mold the final, rubber die is produced. The die is subsequently positioned and fixed on a backing sheet by the printer, the backing sheet usually being scored to provide positioning or centering lines with which the reference lines on the die are aligned to assure proper positioning of the die with respect to a container blank to be printed. The printer then attaches the sheet to a rotating drum of a printing press in the usual manner and the container blank to be printed is fed through the press.

Heretofore, the reference or centering lines for the dies have been efiected in several ways. Commonly, the molder, the one producing the plastic mold, scratched or otherwise provided the lines on the mold which left lines on the die subsequently produced therefrom. By this technique, however, the accuracy of the reference lines was difficult to check and the lines frequently were difficult to change, if inaccurate. Because the lines were frequently scratched or otherwise grooved in the mold, the lines on the printing die were raised above the background surface of the die and occasionaly built up enough ink thereon to cause undesirable printing on the container lank. Other techniques for producing the reference lines involved small variations of the above, and included one or more of the difficulties outlined above.

The present invention relates to an improved method and a device for forming reference lines such as centering lines on a printing die. In accordance with the invention, a reference body having opposed reference lines thereon is positioned and detachably aflixed on the form after it is otherwise complete, the body being placed in a predetermined position usually established by measurements made from the edge of the form, for example. Two of the reference bodies usually are used on opposite sides of the form for either vertical or horizontal centering of the subsequently made printing die on it backing sheet, and four are used on opposite sides, along mutually perpendicular lines, to provide both horizontal and vertical centering. The bodies extend to the same height as the type so as to print images of the reference lines therewith.

After the form is set up, a test proof is printed on translucent paper and the accuracy of the lines is then determined by means of a light box. The light box has a translucent top having scored, mutually perpendicular lines thereon by means of which the accuracy of the placement of the reference bodies can be determined. If the lines are out of position, the bodies can be easily moved on the form to correct this. Additional test proofs can then be printed for additional checks until the precise positioning of the lines is achieved.

The ability to readily check the position of the reference lines is also advantageous in multi-color work wherein the reference lines of the various proofs of the various printing dies can be readily checked by superimposing the proofs on one another on the top of the light box. When the printing is in proper register, the reference lines should then be superimposed and they can be adjusted until this result is achieved.

The mold is next made from the composite form, after the reference bodies are accurately positioned, in the usual manner with a depression being formed therein corresponding to the reference body on the form. The surface of the mold is then ground to remove lines thereon caused by the spacing blocks in the form, in order to provide a smooth background and a more attractive printing die. The reference bodies are then placed in the corresponding depressions with the upper surfaces of the bodies slightly above the surface of the mold because of the reduction in the thickness thereof due to the grinding op eration. The printing die is then made from this mold in the usual manner, leaving slight depressions where the bodies protruded from the mold. The reference lines on the bodies are formed in these depressions well below the printing matter on the die so that ink cannot build up thereon. In addition, the reference lines, by being in the depressions, are closer to the back surface of the printing die so as to be capable of being more accurately aligned with scored lines on the backing sheets.

Each reference body has two major, parallel surfaces, each having a reference line in superimposed relationship with the other. This is essential because the reference line on one major surface of the body prints the reference line on the proof whereas the reference line on the opposite surface of the body forms the final reference line in the printing die. The reference body also preferably has tapered side edges to enable it to be more easily removed from the mold and preferably is also tapered from one end to the other to resist outward movement or slippage in the mold when the die is formed therefrom under pressure.

Lit is, therefore, a principal object of the invention to provide an improved method and reference body for producing reference lines on a printing die, which method and body have the advantages set forth above.

ther objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

FIG. 1 is a view in perspective of a composite form embodying the invention;

FLIG. 2 is a view in perspective of a reference body for use with the form of FIG. 1;

'FIG. 3 is a top view of the reference body;

FIG. 4 is a plan view of a test proof printed with the form shown in FIG. 1, which proof lies on a fragmentary portion of a light box top having mutually perpendicular lines thereon;

FIG. 5 is a view in perspective of a mold made from the form of BIG. 1;

FIG. 6 is a view in perspective of the mold shown in FIG. 5, but after gr-indin g and with reference bodies placed therein;

FIG. 7 is a view in perpective of a printing die formed from the mold of FIG. 6, the die being placed on a backing sheet with reference lines of the die aligned with scored positioning or reference lines on the sheet; and

FIG. 8 is a view in perspective of a modified body.

Referring to the drawings, and more particularly to FIG. 1, a composite form is indicated at 19 and includes a plurality of metal type 12 spelling out the word fragile in this instance. The type 12 is centered in a margin or frame 14 composed of four elongate bars and is centered therein by spacers 16. lThC margin 14 is held in an outer, supporting frame 38 by means of wedges 29, all of which is well known in the art.

In accordance with the invention, inserts or reference bodies 22 are positioned on the spacers 16 so as to be centered with respect to the type 12 and the margin 14. This is usually accomplished by measuring the distance the body 22 is from the margin 14 by means of a conventional ruler. When properly positioned, the bodies 22 are held in place by suitable means such as by tape 24, both sides of which have adherent material thereon.

One of the bodies 22 is shown enlarged in FIGS. 2 and 3. The body 22 has upper and lower major surfaces 26 and 28 which are parallel one to another and which have reference line grooves 39 and 32 lying in a superimposed relationship with respect to one another. The lines 39 and 32 also lie in a common plane perpendicular to both of the surfaces 26 and 28. The necessity of employing two reference lines will be apparent more fully subsequently. The reference lines 30 and 32 can be formed as ridges rather than grooves, the grooves being preferred only because they can be machined more easily.

The major surfaces 2-6 and 28 of the body 22 are of symmetrical, trapezoidal shape with a shorter end 34 of the body lying perpendicularly to both of the major surfaces 26 and 28 so that the body 2-2 can be plawd squarely against the margin 14 with the lines 30 and 32 perpendicular thereto. However, in some instances, the bodies 22 will be spaced back from the margin 14. Side edges 36 and a longer end 38 are tapered so that they can be more easily removed from the mold, as Will be discussed subsequently.

After the composite or form 10 is completed with the bodies 22 in their proper positions, a test proof indicated at 4!} in FIG. 4 is made on a translucent sheet 42 and is placed on a top 44 of a light box, which top has mutually permndicul-ar lines 46 marked thereon. Lines 48 between images i) and 52 printed by the bodies 22 are then aligned with or near the perpendicular lines 46 to determine if the bodies 22 are truly in a symmetrical position with respect to the type 12 and the margin -14. If one of the lines 48 is displaced, the corresponding body 22 can be moved to a new position on the spacers 16 until it is in the proper position. A new print 40 can then be made and the position of the lines 43 checked again until the desired position has been attained.

With the bodies 22 in proper position with respect to the type 12 and the margin 14, a mold 54 of FIG. 5 is made therefrom. [this is accomplished in the usual manner by sprinkling a suitable resinous powder over the form it} and a back board 56 is placed thereon. The combination is then heated under proper pressure and temperature in a press to form the mold S4. The mold 54 includes the backing board 56 with a raised portion 58 formed by the resinous powder around the type 12. The portion 58 has recesses 60 formed by the type 12 and receses 62 formed by the bodies 22. The sides of the recesses 62 flare outwardly due to the tapered edges 56 land 38 of the bodies 22 and ridges 64 are located symmetrically within the recesses 62, the ridges 64 being formed by the upper reference line grooves 39 of the bodies 22. These are the same grooves that formed the lines 48 on the proof 4i? and serve no further purpose because they do not appear in the final die or printing. The recesses 62, although not having a direct affect on the process, are very important because they represent a considerable savings in molding powder. Thus, the amount of molding powder displaced by the bodies 22 can be equal to many dollars over a period of a year, for example.

The raised portion 58 of the mold 54 also has many rough lines 66 thereon formed by the spacers 16 of the form 10. If these lines 66 are left on the mold, they will.

To improve the appearance of the final printing die, the

surface of the mold 54 is ground or sanded to a smooth planar condition as shown in FIG. 6. This operation removes perhaps & inch from the height of the raised portion 53. After grinding, the reference bodies 22 are again placed in the recesses 62, the bodies being identical so that corresponding recesses and bodies need not be remembered. As shown, the bodies 22 now protrude approximately inch above the ground surface of the V raised portion 58 so that the larger major surfaces 28 of the bodies 22 lie above the ground surface. The bodies 22 and the lines 32 are definitely centered with respect to the recesses 69 formed by the type 12 because the bodies are in the recesses corresponding exactly to the positions of the bodies 22 in the form 10. Thus, once the positions of the bodies 22 in the form It? are determined to be proper,

by means of the proof 40, the reference lines will remain exactly the same throughout the entire die-manufacturing process.

With the bodies 22 in position in the mold 54, a final printing die 68 shown in FIG. 7 is produced therefrom in a known manner. At the same time, a control cloth backa ing 70 is vulcanized to the die and the back of the control cloth is subsequently ground to assure that the faces of letters 72, formed by the recesses 60 will be co-planar when the die 68 is laid on a flat surface. The edges of the die 68 are then trimmed and, in this state, the die is usually sent to the container manufacturer.

The die 68 is then afiixed to a backing sheet 74, usually of canvas or Mylar, which has positioning or center lines 76 marked thereon. Reference ridges or lines 78, symmetrically located in shallow depressions 80 formed by the raised portions of the bodies 22 in FIG. 6, are then aligned with the positioning lines 76 to assure that the die 68 is in a precise and proper position, the ridges 78 being formed by the reference line grooves 32 of the bodies 22. The backing sheet 74 is then affixed to a rotary drum of a printing press by means of holes 82 therein or by other suitable means, as is well known in the art.

The fact that the ridges 78 are in the depressions 80 means that the ridges 78 are well back of the letters 72 and cannot build up any ink thereon so as to eventually cause printing thereof. Further, the depressions 80 enable these reference lines ridges 78 to be closer to the sheet 74 and thus enable more accurate alignment of the ridges 78 and the lines 76, keeping parallax to a minimum.

It will be seen from the above that the new method for producing centering lines on the printing die, and the reference bodies for accomplishing the same, have many advantages. Thus, any number of proofs can be run and checked on the light box top 44 to assure that the reference bodies 22 will be in proper position. Further, once the bodies 22 are in position, there can be no human error involved in transferring the reference lines of the bodies eventually to the printing die 68 because of the fact that the bodies 22 are again inserted in the recesses 62 formed by themselves, after the mold 54 is ground. In addition, the final reference lines 73, being located in the depressions 30, cannot build up ink and cause printing thereof as has heretofore occurred.

Referring to FIG. 8, a modified insert or body 84 is shown. This body is similar to the body 22, having two major parallel surfaces and at least two, and preferably four, opposed side Walls slanting toward one of the major surfaces. However, the body 84 is rectangular rather than trapezoidal and fulfills somewhat different purposes. Primarily, the body 84 saves molding powder, as do the bodies 22, as represented by the recesses 62 of FIG. 5. In addition, the body 34 has indicia engraved as indicated at 86 on the larger of the two major surfaces to leave the name or trademark of the producer on the final printing die. The body 84 is not primarily a substitute for the bodies 22 but is used therewith for the above purposes. It is, of course, possible to use either the body 34 or 22 alone, however.

The body 84 is used similarly to the body 22. It is placed on the form if in a position between the type 12 and the margin 14 either before or after the test proof is made but, in any event, before the mold 54 is formed. The body 84 then leaves a recess in the resulting mold to save molding material, with additional bodies producing additional savings in material. One of the bodies 84 then is placed in its recess in the mold 54 after the mold is ground or sanded in the ewe manner as the body 22. The body 84 thus protrudes about inch and leaves a slight depression in the final printing die similar to the depressions 80 but with the name or trademark therein rather than the ridges '73.

Various modifications of the above described embodiment of the invention will be apparent to those skilled in the art and it is to be understood that such modifications can be incorporated without departing from the scope of the invention, as determined by the spirit and tenor of the accompanying claims.

What I claim is:

1. A reference body for producing reference lines on a printing die, said body having two major, parallel surfaces of trapezoidal configurations, side walls between said major surfaces, each of said side walls slanting toward one of said surfaces, each of said surfaces having a reference line thereon, both of said lines lying in a common plane which is perpendicular to both of said surfaces and perpendicular to the parallel edges of said trapezoidal major surfaces, with the side wall which extends between the shorter ones of the parallel edges of the trapezoidal major surfaces being perpendicular to both of said surfaces.

2. A reference body for producing reference lines on a printing die, said body having two major, parallel surfaces, side walls between said major surfaces, some of said side walls slanting toward one of said surfaces, each of said surfaces having a reference line thereon, both of said lines lying in a common plane which is perpendicular to both of said surfaces and to two parallel edges of each of said major surfaces, with one of said side walls which extends between two of the associated parallel edges being perpendicular to both of said major surfaces.

3. A reference body for producing reference lines on a printing die, said body having two major, parallel surfaces, each of said surfaces having a reference line thereon extending substantially completely thereacross between opposite edges thereof, both of said reference lines lying in a common plane which is perpendicular to both of said surfaces.

4. A method of producing a printing die with a depression thereon, said method comprising preparing a composite form, placing an insert on said form in a predetermined position, preparing a mold from said form, grinding a raised surface of said mold, placing an insert in a recess in the mold made by the insert on said form, the insert in the recess protruding above said ground raised surface of said mold, and preparing a printing die from said mold, a depression being left in said die where said insert protruded above said ground raised surface.

5. A method for producing a printing die, said method comprising preparing a composite form, placing a body on said form in a predetermined position, preparing a mold from said form, grinding a raised surface of said mold, placing a body in a recess in the mold made by the body on said form, the body in the recess protruding above the ground raised surface of said mold, and preparing a printing die from said mold, a depression being left in said die where said body protruded above said ground raised surface.

6. A method for producing a printing die with reference lines thereon, said method comprising preparing a composite form, placing two reference bodies with reference lines thereon on said form in predetermin d positions at opposite margins thereof, preparing a mold from said form, grinding a raised surface of said mold, placing two reference bodies in two recesses in the mold made by the reference bodies on said form, the bodies in the recesses protruding above said ground raised surface of said mold, and preparing a printing die from said mold, depressions being left in said die where said reference bodies protruded above said ground raised surface with aligned reference lines being formed in said depressions.

7. in a method for making a printing die which includes the steps of preparing a form, making a mold from said form, grinding a raised surface of said mold, and making a. printing die from said mold, the improvement which comprises placing a reference body on said form in a predetermined position, with a surface thereof at the same height as printing type used therein, and placing a reference body in a recess in the ground mold, which recess is made by the reference body on said form, said reference body being placed in said recess before said die is made from said mold.

8. In a method for making a printing die which includes.

the steps of preparing a form, making a mold from said form, grinding a raised surface of said mold, and making a printing die from said mold, the improvement which comprises placing a body on said form, with a surface thereof at approximately the same height as printing type used therein, and placing a body in a recess in the ground mold, which recess was made by the body on said form, said body being placed in said recess before said die is made from said mold.

9. In a method for making a printing die which includes the steps of preparing a form, making a mold from said form, grinding a raised surface of said mold, and making a printing die from said mold, the improvement which comprises placing two reference bodies on said form in predetermined positions on opposite sides thereof, with major surfaces of said bodies being at the same height as printing type used in said form, and placing reference bodies in two recesses in the ground mold, which recesses were made by the reference bodies on said form, said reference bodies being placed in said recesses before said die is made from said mold.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. 3 123,000 March 3, 1964 Philip. Go Saunders It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1, line 63, for "it" read its column 4 line 54, for "lines" read line column 5 line 34, for "each" read some line 60, for "of" read for Signed and sealed this 28th day of July 1964a (SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ESTON G. JOHNSON Attesting Officer 

8. IN A METHOD FOR MAKING A PRINTING DIE WHICH INCLUDES THE STEPS OF PREPARING A FORM, MAKING A MOLD FROM SAID FORM, GRINDING A RAISED SURFACE OF SAID MOLD, AND MAKING A PRINTING DIE FROM SAID MOLD, THE IMPROVEMENT WHICH COMPRISES PLACING A BODY ON SAID FORM, WITH A SURFACE THEREOF AT APPROXIMATELY THE SAME HEIGHT AS PRINTING TYPE USED THEREIN, AND PLACING A BODY IN A RECESS IN THE GROUND MOLD, WHICH RECESS WAS MADE BY THE BODY ON SAID FORM, SAID BODY BEING PLACED IN SAID RECESS BEFORE SAID DIE IS MADE FROM SAID MOLD. 